The CityLoops project has published its Urban Circularity Assessment (UCA), an urban, economy-wide material flow and stock  accounting method, which paired with indicators, will enable the assessment of material circularity of a municipality or city. The aim of the UCA, developed under the lead of Metabolism of Cities, is to monitor progress toward a Circular Economy (CE) from an economy-wide perspective at the city-level, rather than just at the level of individual products or sectors.

The development of an UCA necessitates a comprehensive approach that takes into account biomass, metals, non-metallic minerals, and fossil energy carriers flows through extraction, imports/exports, processing, use and waste (including collection and treatment) phases. With this information, a consistent mass balance can be performed, in order to establish systematic monitoring of resource utilisation, waste, and recycling across the socio-economic system.

The UCA consists of three main parts: (1) (a) material flow and (b) stock accounting (MFSA), (2) indicators and (3) CE assessment. All these elements are described in more detail in the UCA, which can be downloaded here and here.